1. Field of the Invention
The present invention pertains to a high-pressure rotary-nozzle-head water jet tool suitable for removal of deposits such as scale, rust, paint and the like from various surfaces, and to the means for sealing the connection between the rotating section of the high-pressure water line and its non-rotating section. In particular, this invention pertains to an ultra-high-pressure rotary-nozzle-head water jet tool; such tools are operated at water jet pressures of 10,000 psi to 100,000 psi. An intensifier is used as auxiliary apparatus to achieve such water pressures.
2. Description of the Prior Art
Various high-pressure water jet tools have been described in the prior art. Representative of such tools are those described in the following patents; U.S. Pat. No. 2,985,050, B. G. Schwacha, water jet cutting of hard metals; U.S. Pat. No. 3,526,162 J. A. Wilcox, water jet cutting of rubber; U.S. Pat. No. 3,532,014, N. C. Franz, water jet cutting of cardboard; and U.S. Pat. No. 4,081,200 J. B. Cheung, water jet removal of structural concrete.
In the removal of rust, stripping of paint and similar operations where the operator moves the water jet tool across the work surface, it is highly advantageous to have a nozzle head which rotates in order to provide a wider path of impingement, thereby increasing the operating efficiency of the tool.
In the cutting of rock, drilling of holes and in mining operations employing high-pressure water jets, it is common practice to rotate the water jet head or nozzle. Examples of such are described in U.S. Pat. No. 3,565,191, J. T. Bowen and U.S. Pat. No. 4,369,850, Barker.
A major disadvantage of such rotary water jet tools, whether for rust and scale removal or in mining operations has been the lack of a practical seal for the connection between the non-rotating water supply pipe and the rotating section of the water supply line feeding the nozzle jets. Present ultra-high-pressure water jet tools are limited by the lack of seal means that can withstand the ultra-high-pressures.
Bowen (U.S. Pat. No. 3,565,191) attempts to overcome the problem by eliminating the necessity for ultra-high-pressure seals by rotating the intensifier with the hydraulic drill.
Barker (U.S. Pat. No. 4,369,850) resorts to the use of a section of flexible high-pressure hose connecting the nozzle head with the high-pressure water supply line. This permits the nozzle head to be rotated (orbited) without rotating the flexible hose; no seal is required.
The use of a rotating high-pressure water jet nozzle also is shown in U.S. Pat. No. 4,534,711 , M. Wakatsuki. The use of a seal between the non-rotating high-pressure water line entering the tool and the line feeding the water jets of the nozzle, is eliminated by the use of a section of flexible hose. The flexible hose does not, of itself, rotate, but the end of the hose orbits within the rotating nozzle head.
Water jet tools employing a flexible hose mounted to orbit within a rotating head or an eccentric rotor have the disadvantage that the flexible hose is very expensive because of its construction to withstand ultra-high pressures and has a limited service life. Moreover, replacement of a worn flexible hose requires dismanteling the front section of the tool, a time consuming operation which is expensive and results in loss of operating time.
A very real need exists for a seal that can operate effectively over long periods of operation at ultra-high pressures, that is, at water pressures of over 10,000 psi, not only for water jet tools but also for other ultra-high-pressure equipment.